Self-centering device



Nov. 28 1944. w oc w I 2 ,363,940

' SELF-CENTERING DEVICE Filed May 26, 1943 3 Sheets-Sheet 1 74 Wdierlem Brae I Nov. 28, 1944. w. L. BROCKWAY SELF-CENTERING DEVICE Filed May 26, 1945 3 Sheets-Sheet 2 I 11/) av a A 7 M w c a H 7. 4 6 a m (a, L 2 H n a w a 0 B7 I z W J 7 2 J f? 1/9. I [l T v 6 a 1944- w. L. BRo cKwAY SELF-CENTERING DEVICE Fil ed May 26, 1943 5 Sheets-Sheet s Inventor Mdzerlemj Brockwy y mm Patented Nov. 28, 1944 p y l f ll 2363,1340] SELF-(ENTERING avies. 1 'WalterLeroyBrockway, Auburn. Township, Ge-

auga County,,,0hio, assignor. of one-half to MaxwelliGreenler; Chardon, and one-fourth to Lewis M.jl3 rockway, Chagrin Falls,jqhio C ApplicationMaysZfi, 1943, :Serial No. 488,607:

. 'I'h isinvention"reIatesto neW and useful improvements in centeringdevices, more particu larly to a self-centering device,which=has= as its principalflobject to accurately center drill shafts and accomplish this'in onlyaws'mall fractionof the. timetaken when the vcenter is :found by the squara center punched andthen centered on the drill press.

Another important object-ofthe invention is t provide a self-centering device which can be quickly applied to a drill press which in use will i be substantially foolproof and positive acting at all times. i

A further object of the invention is to provide a centering device of the character stated where- 3 in the elements employed for centering work can be readily adjusted to accommodate work of various sizes. l

Other objects and advantages of the invention will become apparent to the reader of the following description.

In the drawings:

tion 6.

spondingspringca'se l2. These cases l2 are secured byears 13 and screws H to the lower case;

6 andin. each of these cases I2 is acoiled coma pression spring 15, the lower end of which rests on the .bottomofthecorresponding case; l2 while itsupperend isimpinged against the under side ofjthewcorresponding.lug l I. Thus it can be seen, tha-tgthesprings l5-serve to maintain the lower sectionefi llr ed downwardly and with the spring pressure against a piece of work such as a shaft IGto be centered, that-is, when the upper section 6 is suitably secured to the shank iii of a drill press by set screw or the like l9.

Numeral 2!! denotes a drill chuck inwhich a center drill 2i can be held and this drill depends through the opening I in the bottom of the see- As is apparent in Figures 1, 2, and '1, the lower section 6 has a plurality of radial slots 22 in the bottom thereof to receive the upper portions of centeringfguides'23, each of which has transverse Figure lis a front elevational view ofthe device, showing the same applied to work.

Figure 2 is a fragmentary side elevational view.

Figure3 is a vertical sectional view through the device shown applied to work.

Figure 4 is a bottom plan view of the device. Figure 5 is a perspective view of the lower section of the device.

Figure 6 isa perspective view of one of the guides. n

Figure '7 is a fragmentary sectional view through the lower portion of the lower section.

Figure 8 is a top plan view of the device. Figure 9 is a bottom plan view of the device.

. Figure 10is a section on line Ill-l 0 of Figure 2.

Figurell is a section on line l|-Il of Figure 3.

Referring to the drawings wherein like nuthe device consists of an upper section 5 and a merals designate like parts, it can be seen that ribs or teeth 24 adapted to be engaged by rotary adjusting screws 25 seated in more than semicylindrical-shaped recesses 26. These adjusting screws 25 are simply rotatably mounted freely within the recesses 26 and areprevented from becoming displaced by, small set screws 21 which block their displacement from the said recesses. The outer ends of thescrews 25 have tool engageable sockets 28.

The inner edge portions of the centering guide 23 are beveled, as at 29 to engage work It adjusted in FigureB.

Secured to the bottom of the section 6 by screws or the like 3.0 are four segmental shaped plates 3|, each 'platehaving one edge portion engaging into a groove 32 in one side of a correspending centering guide 23, as is. clearly shown in Figures 1 and 2 of the drawings. k In other words, these edge portions of the segmental plates 3| serve to guide the centering guides 23 lower section 6, both being of cylindrical shape,

the upper section 5, being open at both its top and bottom, while the lower section 6 is only fully open at-its top and formed with a small opening I in the central portionof its bottom.

The lower section 6 has a pair of vertically disposed guide grooves, 8, 8'for receiving guide bars 9, 9 which are vertically disposed on the upper section 5 and depend a substantial distance below the same, these bars being secured to the upper section 5 by screws or rivets l0. Each guide bar 9 has a laterally disposed lug II which isdisposed into the upper portion of a correand prevent displacement thereof as they are adjusted by the screws 25 to accommodate work of various sizes.

Obviously, by pushing up on the lower section 6, work can be easily released and new work quickly inserted in place.

A fitting 23a for a sight lubricator can be provided for the lower section 6.

Numeral 24a denotes a table for the drill press. While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size, and

materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the invention, what is claimed as new is:

1. A self-centerng device for drills comprising a tubular upper section for fitting about a drill shank above a chuck and adapted to be de-' tachably secureditherebh, a up sh ned ow section for fitting about the chuck in'downwardly spaced relation to the upper section and formed at thecenter of its bottom with an opening to accommodate a bit carried by the chuck, the lower section being formed with vertically extending circumferentially spaced grooves, yer: tically disposed guide bars carried by the upper side edges for engaging work and centering th bit over the work.

2. A self-centering device for drills comprisin a tubular upper section for fitting about a drillshank above a chuck a. cup-shaped lower section for fitting about the chuck and having its bottom formed with a central opening to accommodatea, bit carried by the chuck, said lower section being shittable vertically about the chuck toproject the bit downwardly through the open- "ing and yieldably held against upward movemer t; the bottom of said lower section being section and extending downwardly therefrom 1 into said grooves, lugsprojecting outwardly from upper portions of said bars, spring casings carformed with grooves radiating from its central openingand (havingtheir upper portions formed with channels, screws rotatably mounted in said ch'anne'lsand. adapted to be turned from their outer ends, workengaging guides extending riedby the lower section and extending upwardly:

downwardly from said lower section and having their upper sides slidably engaged in said grooves and in threaded engagement with said screws for adjustment radially of the bit wh n-1111 screws are turned-Said guides being formed with side giroovesnear their upper ends, and plates detachably mounteciiaeeinst the unde line 9fthe bottom of the lower section with vSide edge portions engaged in grooves of the worli enzaz in uides to hold the guides in the rooves-m which they operate. a WAL'IERIMRQY BROCKWAY. 

